The present invention relates to an electromagnetic noise absorber that is attached around an electric cable to attenuate noises transmitted through the electric cable.
A typical known electromagnetic noise absorber of this type is constituted, for example, by a plastic housing and a ferrite sintered body housed in the plastic case. However, ferrite sintered bodies are generally easy to break and hard to bend. Accordingly, the above electromagnetic noise absorber is usually configured to be attached to only a small part of an electric cable, and thus is mostly not attachable to a wide range of the electric cable in a longitudinal direction.
Another electromagnetic noise absorber of this type which is attachable to a wide range of the electric cable in a longitudinal direction is also proposed (for example, in Japanese Unexamined Patent Application Publication No. 2003-133780). The proposed electromagnetic noise absorber is constituted by mixing ferrite powder into a resin material to obtain a magnetic composite and forming the magnetic composite into a tubular shape.
The proposed electromagnetic noise absorber, which is unlikely to break even when configured to be relatively long, may be attachable to a wide range of the electric cable in a longitudinal direction. It is also proposed to make a spiral slit in the tubular electromagnetic noise absorber (see FIGS. 4(B) and 4(C) in Japanese Unexamined Patent Application Publication No. 2003-133780). This configuration facilitates easier insertion of an electric cable, and thus may achieve an improved convenience.